Coach Chip Kelly explained Wednesday that Ertz's playing time has waned because it would be an "injustice" to take Brent Celek off the field.

"Brent's an outstanding blocker," Kelly said, via NJ.com. "I think he may be the best blocking tight end in the league."

Of the 61 tight ends ranked by Pro Football Focus, Celek is fourth in blocking.

Ertz not only agrees with Kelly's assessment of Celek's ability, but also went as far as to suggest New Orleans Saints All-Pro Jimmy Graham would find snaps hard to come by in the Eagles' offense.

"Probably not, to be honest," Ertz said, of a hypothetical role for Graham. "I don't want to take anything away from Jimmy, but the things I've seen, he is more of a pass-catching tight end. In this offense we are a run-first team and we don't sub because we go at (a fast pace)."

Kelly is one of the brightest offensive minds in the game. There's little question he would find a way to highlight Graham's mismatch potential if given the opportunity.

Still, the larger point stands that different schemes require different traits, especially in today's era of specialization and multiple personnel groupings.